The present invention relates generally to an improvement in a microfilm retrieval system for retrieving a certain specified microimage from multiple items of information recorded on a suitable storage medium such as a microfiche, and more particularly to an improved system with information updating capabilities by which an operator can register a new microfiche with its identifying information in a microfiche library.
It is customary in the art of microfilm retrieval that a specified microfiche containing a specified microimage to be selected is automatically retrieved from a number of microfiches each having a capacity of, for example, 98 or 72 microimage or frames, the thus retrieved microimage being moved with respect to X and Y axes coordinates in a manner to project it onto a viewing screen.
In conventional microfilm retrieval systems, when it is desired to retrieve a specified microimage, the operator must look up address information relating to such specified microimage by, for example, viewing a look up table describing multiple items of index information (i.e., primary information consisting of title information) and corresponding multiple items of address information (i.e., secondary information consisting of microfiche identity number, microimage X and Y axes coordinates). The secondary information thus preselected is entered via a keyboard such that only one microfiche containing the specified microimage is automatically retrieved from a microfiche library for magnification and projection onto a viewing screen.
However, in the prior art systems, in the case in which an operator adds a new microfiche and updates the microfiche library, it is necessary that multiple items of index information and multiple items of corresponding secondary information are additionally hand written onto a look up table. This requires such labor and creates a possibility of registration error. Moreover, the selection operation for such additional information difficult because the additional items of information may be generally stored in random order.
It is, therefore, an object of the present invention to provide an improved microfilm retrieval system having information updating capabilities which enable the operator to add comparatively easily and accurately new microfiches to a microfiche library.